Puzzles like these keep brains sharp and hands busy for hours, making them a perfect holiday/winter months gift for school-aged kids. Lab Test Games are extra-large, science-inspired brainteasers for older children or grown-ups that will put all that gray matter to good use. Each puzzle has a different concept and difficulty level. Once users have completed the Atom, the Molecule poses the next challenge, and then the Particle will stump you. Up for the ultimate challenge? You can tackle the Cell. And you thought passing chemistry was tough!